SotA S18: move DA transformation to lua

[ci skip]

data/campaigns/Secrets_of_the_Ancients/scenarios/18_Abandoned_Outpost.cfg

@@ -148,49 +148,19 @@ Now the process is complete for both of us. I posted a guard so nothing could ha
         [/allow_recruit]
 
         # This section changes all *existing* units so that they have liches in their
-        # advancement trees. As of 1.12 at least, [modify_unit] doesn't apply to
-        # the recall list, so we have to do it the long way.
-        [store_unit]
-            [filter]
-                type=Dark Adept SotA, Dark Sorcerer SotA
-            [/filter]
-            variable=DA  # Even though it might actually be a DS.
-        [/store_unit]
-
-        [for]
-            array=DA
-            variable=i
-            [do]
-                [if]
-                    [variable]
-                        name=DA[$i].type
-                        equals=Dark Adept SotA
-                    [/variable]
-                    [then]
-                        [set_variable]
-                            # Custom DA's will advance to normal dark sorcerers
-                            # which will fix them.
-                            name=DA[$i].advances_to
-                            value=Dark Sorcerer
-                        [/set_variable]
-                    [/then]
-                    [else]
-                        [set_variable]
-                            # Custom DS's just get the other advancement added.
-                            name=DA[$i].advances_to
-                            value=Necromancer,Lich
-                        [/set_variable]
-                    [/else]
-                [/if]
-                [unstore_unit]
-                    variable=DA[$i]
-                [/unstore_unit]
-            [/do]
-        [/for]
-
-        [clear_variable]
-            name=DA
-        [/clear_variable]
+        # advancement trees. As of 1.14 at least, [modify_unit] doesn't apply to
+        # the recall list, same for [transform_unit].
+        [lua]
+            code = <<
+                for i, u in ipairs(wesnoth.get_recall_units { type = 'Dark Adept SotA, Dark Sorcerer SotA' }) do
+                    if u.type == 'Dark Adept SotA' then
+                        u:transform('Dark Adept')
+                    elseif u.type == 'Dark Sorcerer SotA' then
+                        u:transform('Dark Sorcerer')
+                    end
+                end
+            >>
+        [/lua]
 
         # We need to change all existing bats to normal types instead of SotA types
         # so they are drawn above terrains. SotA bats were necessary for the ship